by Zero1 » Tue May 22, 2007 6:13 pm
Unfortunately since most of the people who develop tools such as Haali's splitter, and perhaps VSFilter are MKV fans, MP4 softsub support is last on their list, especially since .SSA and .ASS are working - they would rather improve those than work on 3GP softsubs (which to an extent I can appreciate).
At the moment, Haali's splitter "supports" them; I use the term loosley because it never really fully supported, or rendered them they way they are supposed to be. What it did was convert them to SSA on playback, so the positioning was slightly off and styling was lost. Since then Haali said he "fixed" 3GP support, but now it's probably worse than it was before - a lot of my samples that work in Osmo4 do not show subs (or show them offscreen) using Haali.
I believe MPC has it's own internal MP4 splitter - and that renders them quite well.
3GP subs require work by people that appreciate the spec and use; unfortunately people would rather work on "open software" that gets no industry support. IMO it's a waste of time - I like SSA and ASS for hardsubbing because it's very versatile - but I don't think it's well suited as a distribution format. Each to their own; I'm appreciative and greatful of the work these people do, but a little dissapointed that 3GP is going nowhere.
3GP isn't as restricted as people think - it largely relies on the renderer to make it look decent as it is a format originally designed for mobile phones. Of course on mobile phones you have low CPU power, and the ability to show the subs off the main video (eg in the letterbox), so outline is not required - however a decent renderer should have an outline by default, and the ability for the user to set basic defaults for styles. Of course you are able to specify position, colour, and where to put the subs in 100% or fullscreen (for instance the subs are overlayed on the video at 100%, but in fullscreen they are displayed in the letterbox), it also has basic karaoke, clickable links, font type and size setting.
As for softsubs in MP4 - you need SRT as input and you can add it in MP4Box which converts it to 3GP timed text, you need to use "-add" to add the stream and "-ttxt" to convert it. I softsubbed an MP4 AMV once for the hell of it, and it used to display fine using Haali's splitter and VSFilter, but now it doesn't. AFAIK it still works in Osmo player, which is what you should use for reference (Osmo player also supports MP4 Menus and in program controls like in HD-DVD.)